i had an allergic reaction to shellfish, the rashes, sore throat and headache have all gone but my knees, elbows ,some of my fingers are very painful to the extent that I can barely lift a cup and struggled tl get out of bed. the symptons have lasted nearly a week. I was told by my doctor to take painkillers and piriton anti histemine. i have done so. Do i need to worry that these symptoms persist?